well i personally think the "track cut warning/black flag" is actually to keen on most tracks you watch any racing and the old and new and the only time there is a penalty for this action is IF the car involved actually makes a position in the act of the corner cut and doesn't allow the position to be taken back.

also there are times you get black flagged when you didn't even do anything wrong eg somebody tries an overtake and nuges you off the tarmac you loose time on the grass then you end up having to pit and loose a ton of time on top of this

i have actually changed my opinion on track cutting and IF you can push to the limit and cut the corner without getting the warning go for it.
i personaly try not to get close to the limit cos it always seems to hit me with a warning even when i have 2 wheels ON the tarmac ::